The opening party for the new Spaulding Rehabilitation Hospital in Charlestown had to be canceled on Friday night, but it managed to come together Boston strong on Saturday. A busy Mayor Tom Menino managed to attend the affair, which drew almost 500 supporters, including Spaulding trustee Tedy Bruschi, Citi Center for the Performing Arts president and CEO (and Spaulding trustee) Josiah Spaulding Jr., and Spaulding Rehabilitation Network president David Storto. The night included a performance of “Stars and Stripes Forever” by members of the Boston Pops, who were followed by the band Soho, which played a rousing rendition of “Sweet Caroline.” Not surprisingly, guests sang along.